The present invention relates to the use of an optical input, such as an optical input used for the calibration of an indicator, such as a fuel gauge on a motorized vehicle. In some applications, certain indicators or gauges will give an indication of a system parameter, such as a level of fuel in a motorized vehicle. On occasion, adjustments or recalibration of the system, or of the gauges monitoring and displaying parameters of the system, may be desired. Adding input devices for the calibration, such as switches and the like, is not always practical.
For these and other reasons, there is a need for the present invention.